| Autor: |
Laura E. Navas, Fernando D. Martínez, María E. Taverna, Morgan M. Fetherolf, Lindsay D. Eltis, Verónica Nicolau, Diana Estenoz, Eleonora Campos, Graciela B. Benintende, Marcelo F. Berretta |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
AMB Express, Vol 9, Iss 1, Pp 1-10 (2019) |
| Druh dokumentu: |
article |
| ISSN: |
2191-0855 |
| DOI: |
10.1186/s13568-019-0748-y |
| Popis: |
Abstract Laccases are multicopper oxidases that are being studied for their potential application in pretreatment strategies of lignocellulosic feedstocks for bioethanol production. Here, we report the expression and characterization of a predicted laccase (LAC_2.9) from the thermophilic bacterial strain Thermus sp. 2.9 and investigate its capacity to delignify lignocellulosic biomass. The purified enzyme displayed a blue color typical of laccases, showed strict copper dependence and retained 80% of its activity after 16 h at 70 °C. At 60 °C, the enzyme oxidized 2,2′-azino-di-(3-ethylbenzthiazoline sulfonate) (ABTS) and 2,6-dimethoxyphenol (DMP) at optimal pH of 5 and 6, respectively. LAC_2.9 had higher substrate specificity (k cat/K M) for DMP with a calculated value that accounts for one of the highest reported for laccases. Further, the enzyme oxidized a phenolic lignin model dimer. The incubation of steam-exploded eucalyptus biomass with LAC_2.9 and 1-hydroxybenzotriazole (HBT) as mediator changed the structural properties of the lignocellulose as evidenced by Fourier transform infrared (FTIR) spectroscopy and thermo-gravimetric analysis (TGA). However, this did not increase the yield of sugars released by enzymatic saccharification. In conclusion, LAC_2.9 is a thermostable laccase with potential application in the delignification of lignocellulosic biomass. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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